With development of science and technology, OLEDs have been widely used. As compared with liquid crystal displays (LCDs), OLEDs have advantages of self-light emitting, rapid response, wide viewing angle, high luminance, bright colors, light weight and thin thickness, and the like, and are regarded as a next generation display technology. Nowadays, OLEDs tend to be large scale and large size.
Current methods for preparing an OLED light emitting layer mainly include two kinds of processes, i.e., a vacuum evaporation process and a solution process. As compared with the vacuum evaporation process, the solution process has advantages of low equipment cost, high material utilization ratio, high precision for large-size product mask alignment, and the like. Commonly used solution process includes a spin coating process, an ink jet printing process, a nozzle coating process, and the like. With development of ink jet printing technology, the printing position of a material to be printed (e.g. an organic material constituting a light emitting layer) can be precisely controlled at present.
However, current pixel defining layers, preparation methods thereof and OLEDs still need to be improved.